1. Field of Invention
The present invention relates to communication devices, and more particularly to wireless devices. The present invention is also related to checking integrity of devices connected to wireless devices, and particularly to checking integrity and verification of proper antenna devices connected to wireless communication devices.
2. Discussion of Background
There are a number of reasons that manufacturers prefer to have antennas that are connectorized. This allows customers to choose among a variety of antennas, select the best one for a given situation, and attach them on their own. Connectorized antennas can also be more convenient for manufacturing. They also allow easy customization of products for a given regulatory domain. If antennas become broken, they can be replaced by the user. Testing of units in the field is easier if the antennas are attached with standard connectors.
However, there are a number of reasons that not any antenna should be attached. Some antennas would violate FCC rules due to excessive gain. Other antennas could damage the unit by being of the wrong impedance or frequency and reflecting power back to the transmitter. It is therefore desirable to have a method which insures that a device will operate only when antennas that are appropriate to that device are connected.
In the past, people have used “unique” antenna connectors to attempt to prevent users from connecting antennas that violate FCC rules or otherwise be inappropriate for use with the device. An example of such a unique antenna connector is a standard connector in which the threading has been reversed such that it will not mate with the traditional form of the connector. FIG. 1 illustrates another “unique” antenna connector, in a cell phone application, where an antenna 40 is connected to a cell phone 30, via an outer and inner connector 15/25. Note the unique features on inner connector 25 that must mate with corresponding surfaces in outer connector mate 15. However, such “unique” connectors are easy to duplicate and often become common place. Furthermore, the FCC has required UNII devices operating in the 5.15–5.25 GHz band to use “integral antennas,” and, an easily duplicated “unique” connector is insufficient to insure integrity.